Consensus sequence L/PKSSLL mimics crucial epitope on Loop III of Taiwan cobra cardiotoxin

• Published in: Biochemical and biophysical research communications 2009-09, Vol.387 (3), p.617-622
• Main Authors: Wang, Ping-Chieh, Loh, Kah-Sin, Lin, Shih-Ting, Chien, Tzu-Ling, Chiang, Jen-Ron, Hsieh, Wen-Chin, Miao, Bor-Lin, Su, Cheng-Fu, Yang, Wen-Jen
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antibodies - immunology; Bungarus multicinctus; Cardiotoxin; Cobra Cardiotoxin Proteins - chemistry; Cobra Cardiotoxin Proteins - genetics; Cobra Cardiotoxin Proteins - immunology; Consensus Sequence; Epitope; Epitope Mapping; Epitopes - chemistry; Epitopes - genetics; Epitopes - immunology; Female; Mice; Mice, Inbred BALB C; Molecular Mimicry; Molecular Sequence Data; Naja naja atra; Neutralization Tests; Peptide Library; Phage display; Protein Structure, Secondary; Taiwan cobra ( Naja naja atra)
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2009.07.097

Phage display is effective in screening peptides that mimic venom’s neutralizing epitopes. A phage display cyclized heptapeptide library (C7C library) was panned with purified divalent antivenin IgG, which neutralizes Naja naja atra venom (NAV) and Bungarus multicinctus venom (BMV). The selected heptapeptide sequences were aligned with known protein sequences of NAV and BMV in GenBank. One of the four consensus sequences, L/PKSSLL, mimicked the crucial epitope on Loop III of Taiwan cobra cardiotoxin that is associated with the venom’s lethal potency. In dot blot analysis, several clones showed varying reactivities for NAV monovalent antivenin and lesser cross-reactions with BMV monovalent antivenin. The KSSLLRN-carrying phage occurred four times in selected clones and showed the strongest reactivity to NAV monovalent antivenin. Furthermore, the QDSLLPS-carrying phage also presented significant dot blot signal, indicating that the SLL sequence shared by these two clones may be a crucial antibody-binding site.